Thread lubricating device



Dec. 22, 1964 A. J. COBERT 3,162,544

THREAD LUBRICATING DEVICE Filed Oct. 8, 1962 Jaw/2Z7 Mani/W612 United States Patent Ofilice Patented Dec. 22, 1964 3,162,544 THREAD LUBRICATING DEVICE Arthur J. Cohert, 309 S. Union St., rConcord, NC. Filed Oct. 8, 1962, Ser. No. 228,828 4 Claims. (Cl. 1181Z5) The present invention relates to a thread lubricating device and is herein disclosed as embodied in a device for lubricating thread for use in knitting machines.

Thread lubrication in knitting machines is employed normally to reduce static electricity, to reduce wear of contact parts with the thread, and to reduce picks and pulls in the unfinished blanks before the finishing operation. Wick-type thread lubricators are normally employed for this purpose consisting generally of a bottle which contains the lubricant and a wick with which the feeding thread is frictionally engaged so that the thread may take up a small quantity of lubricant. Wick thread lubricators of the type above referred to have the disadvantage that they require frequent attention, the flow of lubricant to the feeding thread tends to be uneven and uncertain, and the lubricator is extremely wasteful in that a considerable amount of excess oil is brushed onto the thread, most of which is thrown off into the air in the knitting room. During operation the thread very soon starts cutting into the wick which changes the friction or drag of the thread with resultant variations in loop formation.

Capillary-type thread lubricators known in the art have specific disadvantages in that since the rate of flow is directly dependent upon the size of the capillary tube, there is a tendency to submerge the thread in the lubricant with the result that the thread is coated to excess, or if the tube is made larger, the capillary action may not be sufli cient to bring any lubricant at all into engagement with the feeding thread.

It is a principal object of the invention to provide an improved thread lubricating device which will operate consistently over an extended period of time to provide an optimum amount of lubrication to the feeding thread.

A feature of the invention consists in the provision of a capillary tube which is of relatively large diameter having only a slight capillary action to raise the level of thread lubricant contained therein, and a wick loosely compacted within said tube cooperating with the wall of said capillary tube to draw lubricant upwardly over the relatively great distance of an inch or more and to maintain a tiny bubble of said lubricant in said tube above the end of the wick where it is continuously engaged with a feeding thread guided across the lubricator at a level slightly above and out of contact with said wick.

in the preferred form of the invention shown, a wick is provided which is comprised of non-absorbent fibers having smooth external surfaces, said fibers preferably being of small diameter and of sufficient number so that a capillary action is set up between said surfaces including the surfaces of said fibers and the wall of the capillary tube which causes a small but continuous supply of lubricant to be continuously lifted the length of the Wick and sufficiently above the wick to form a small bubble of lubricant thereon.

With the above noted and other objects in view as may hereinafter appear the several features of the invention consist also in the devices, combinations and arrangement of parts hereinafter described and claimed which together with the advantages to be obtained thereby will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a view in side elevation of a thread lubricating bottle provided with a vertically disposed oil supply tube and with the guiding means for passing thread across the upper end of said tube;

FIG. 2 is a plan view of the thread lubricating bottle shown in FIG. 1 with a portion of the overlying strap broken away to show the top of the supply tube;

FIG. 3 is a detail sectional view on an enlarged scale of the upper portion of the thread lubricating device including the lubricant supply tube, supporting sleeve for the tube, and the guiding and stripping washers between which the thread is guided across the upper end of the thread lubricating device;

FIG. 4 is a detail sectional view taken on a line 44 of FIG. 3 looking from the left; and

FIG. 5 is a plan view on an enlarged scale taken on a line 55 of FIG. 3 showing the manner in which the thread creases or wipes against the bubble of lubricant at the upper end of the lubricant supply tube and wick without breaking same.

The thread lubricator which forms the subject matter of the present invention comprises a glass bottle 10 having a screw cap 12 to which is attached an inverted U- shaped frame 14 having mounted in the side members thereof two ceramic eyelets 16 and 18 which are held in place by suitable retaining rings 29, 22. The thread 24 to be lubricated is threaded through said eyelets and through an aperture 25 in the upper end of a tube 26 forming an integral part of a lubricating device generally designated at 28. While any suitable lubricant may be employed, it is preferred to use a fine grade of machine oil for lubricating the thread.

The lubricant supply tube 26 is preferably of a ceramic material providing a hard smooth interior surface suitable for use as a capillary. In actual practice the interior diameter of said tube 26 may be in the order of .050 inch. The external diameter may be assumed to be /8 inch. The tube 26 is press fitted into an externally threaded sleeve 31} which is made preferably of nylon. The lubricant supply tube 26 together with its supporting sleeve 3% projects downwardly through an aperture formed in the screw cap 12 and is held by means of two retaining nuts of nylon 32, 34 tightened respectively against the top and underside of the cap 12. The nylon sleeve 30 is de formed suiliciently by said tightening action of the nuts to grip still more tightly the tube 26 press fitted therein.

The thread is guided by the eyelets 16, 18 through the transverse aperture 25 in the lubricant supply tube 26, bebeing further supported by means of an underlying collar 38 of a hard ceramic material which surrounds the lubricant supply tube 26 and rests upon the upper end of the sleeve 30, and by an overlying collar 40, also of a hard ceramic material which presses down on the thread.

The interior of the lubricant supply tube 26 is loosely filled with strands 42, preferably of small denier and composed of a hard, smooth surface, non-absorbent material suitable for drawing lubricant upwardly from the bottle 1% in which the lower end of the lubricant supply tube 25 is immersed. While in the embodiment of the invention illustrated the wick is composed of strands of hemp, it is contemplated that any suitable material having non-absorbent, hard surface characteristics may be used.

The hard surfaces of the hemp strands cooperate with the internal surface of the lubricant supply tube 26 to lift said lubricant by a sort of capillary action within the tube into contact with the traveling thread.

A feature of the lubricating device here disclosed con sists in the fact that the filler comprising the hemp strands extends upwardly to a point slightly below and out of contact with the thread. The arrangement is such that lubricant is drawn up through the tube the full length of the wick, and slightly beyond, so that a tiny bubble 44 of lubricant forms above the end of the wick. This additional rise of the lubricant is brought about by the capillary properties of the tube itself, and is just sulficient to cause the lubricant to contact with and moisten the traveling thread.

The operation of the lubricating device will be briefly described as follows:

Lubricant is drawn upwardly through the tube 26 and wick 42 through the distance of about one inch from the surface level of the lubricant to the upper end of the wick which, as best shown in FIGS. 3 and 4, terminates just beneath and out of contact with the traveling thread 24. As previously noted the wick 42 may be of any suitable absorbent material such as cotton, but preferably consists of a group of loosely compacted non-absorbent hard surface fibers such as hemp. With this arrangement the rate of feed of lubricant to the upper end of the wick is readily regulated by increasing or decreasing as may be desired the number of fibers comprising the wick. The diameter of the inner wall of the tube 26, as previously noted, is chosen so that a capillary action is induced which, in addition to assisting the fibers 42 in raising the level of the lubricant to the upper end of the wick, will cause the surface level of the lubricant to be raised above the end of the wick by an accurately predictable small amount thus producing the small bubble 44 of lubricant which extends above the end of the wick.. The bubble thus formed is so positioned that it is engaged by and is creased, but preferably not broken, by the feeding thread. With this arrangement of the lubricating device, a very small amount of the lubricant is transferred to the traveling thread. The fact that the thread is not fully immersed in or saturated with lubricant insures that only that small amount of lubricant will be taken up by the thread which is necessary for the proper lubrication thereof.

The arrangement shown, and more particularly the preferred construction in which the lubricant is drawn upwardly entirely by the capillary action of a wick composed of hard surface fibers, has the further advantage 4 ing formed adjacent the upper end thereof an aperture adapted to permit passage of the thread transversely through said tube, guiding and stripping means for the thread passing through said aperture, a wick extending from said container upwardly through said tube to a point slightly beneath and out of contact with the path in which the thread is guided, said capillary tube having an internal wall of a substantial diameter chosen for raising the lu bricant level above said Wick into the path of travel of said thread. i

2. A device for lubricating thread in transit according to claim 1 in which a capillary tube having an internal wall diameter of approximately .050 is employed for raising the lubricant level above said wick into the path of travel of said thread.

' 3. A device for lubricating thread in transit according to claim 2 in which the wick is formed of strands of hemp loosely compacted to provide with the internal wall of said tube a capillary for raising the lubricant level in the tube to the upper'end of said wick.

4. A device for lubricating thread in transit having in a combination a lubricant container including a cap coverthat a control of the rate of feed and replacement of lu- 1. A device for lubricating thread in transit having in combination a lubricant container, a capillary tube having said container, a capillary tube of ceramic material having formed adjacent the upper end. thereof an aperture to permit passage of the thread transversely through said tube, a screw threaded sleeve of nylon within which said capillary tube is supported, and nylon nuts screw threaded to said sleeve for engaging a portion of the cap therebetween, guiding and stripping means for the thread passing through said aperture including a pair of ceramic Washers overlying said sleeve element at the level of said aperture, a wick composed of strands of a hard surface non-absorbent material loosely compacted within and extending upwardly from said container and through said tube to a point slightly beneath and out of contact with the path through which the thread is guided, said capillary tube having an internal wall of a substantial diameter chosen for raising the lubricant level above said Wick into the path of travel of said thread.

References Cited in the file of this patent UNITED STATES PATENTS 1,934,796 Friederich Nov. 14, 1933 

1. A DEVICE FOR LUBRICATING THREAD IN TRANSIT HAVING IN COMBINATION A LUBRICANT CONTAINER, A CAPILLARY TUBE HAVING FORMED ADJACENT THE UPPER END THEREOF AN APERTURE ADAPTED TO PERMIT PASSAGE OF THE THREAD TRANSVERSELY THROUGH SAID TUBE, GUIDING AND STRIPPING MEANS FOR THE THREAD PASSING THROUGH SAID APERTURE, A WICK EXTENDING FROM SAID CONTAINER UPWARDLY THROUGH SAID TUBE TO A POINT THE THREAD IS GUIDED, SAID CAPILLARY TUBE HAVING AN INTERNAL SLIGHTLY BENEATH AND OUT OF CONTACT WITH THE PATH IN WHICH WALL OF A SUBSTANTIAL DIAMETER CHOSEN FOR RAISING THE LUBRICANT LEVEL ABOVE SAID WICK INTO THE PATH OF TRAVEL OF SAID THREAD. 